Subsequent Events (Detail) (Subsequent event, Public Offering, Common stock, USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended
	Apr. 30, 2015
Subsequent Events
Value of shares sold by the entity	$ 44.3
Sale of common stock (in shares)	25,300,000
Sale of common stock (in dollars per share)	$ 1.75
Net proceeds from issuance of common stock	$ 41.8
Largest Shareholder Members Of Board Of Directors And Entities Affiliated With Directors
Subsequent Events
Sale of common stock (in shares)	7,257,142
Underwriters Option
Subsequent Events
Sale of common stock (in shares)	3,300,000